Revolving door

ABSTRACT

A revolving door having upper and lower mechanisms mounted in the doorway about a vertical axis, with the upper mechanisms suspended from a roof of the doorway and the lower mechanism in the floor. The door leaves are in upright and spaced apart relationship to move as a unit with the mechanisms about the vertical axis. In a preferred embodiment, air sealing means is provided to prevent excessive air movement past inner extremities of the leaves.

United States Patent 1 Rush et al.

[ 1 June 5, 1973 541 REVOLVING DOOR [75] Inventors: Carl Jackson Rush, Agincourt, Ontario; Horst Appelmann, Day Ridges, Ontario, both of Canada [73] Assignee: C. J. Rush Limited, Scarborough, Ontario, Canada 221 Filed: Jan. 7, 1972 21 App]. No.2 216,177

[30] Foreign Application Priority Data Feb. 18, 1971 Canada ..l05,677

[52] US. Cl. ..49/44 [51] Int. Cl. ..E05d 15/02 [58] Field of Search ..49/42-45 [56] References Cited FOREIGN PATENTS OR APPLICATIONS l,l98,246 7/1970 Great Britain ..49/44 Primary E xaminerJ. Karl Bell Att0rney- Rogers, Bereskin & Parr [57] ABSTRACT A revolving door having upper and lower mechanisms mounted in the doorway about a vertical axis, with the upper mechanisms suspended from a roof of the doorway and the lower mechanism in the floor. The door leaves are in upright and spaced apart relationship to move as a unit with the mechanisms about the vertical axis. In a preferred embodiment, air sealing means is provided to prevent excessive air movement past inner extremities of the leaves.

18 Claims, 9 Drawing Figures REVOLVING DOOR This invention relates to a revolving door of the type having door leaves mounted to project radially for rotation about an upright axis, the door leaves being spaced angularly about the axis. More specifically, the invention relates to a revolving door having leaves which are adapted to fold under abnormal pressure such as occurs under panic conditions, so as to create an open passage through the doorway. Revolving doors of this type are often referred to as collapsible revolving doors.

Many different types of collapsible revolving doors are available. However, such doors generally suffer from at least one of two major defects. Firstly, a costly and complicated mechanism has usually been required to retain the door leaves normally in their uncollapsed or extended position and to guide the leaves to their collapsed position, the mechanism including bearing assemblies for mounting a central post connecting upper and lower mechanisms. Secondly, much of the mechanism, and in particular the centre post, has been exposed to view creating an unsightly appearance for the door.

Accordingly, it is an object of the present invention to provide a collapsible revolving door having upper and lower mechanisms independently mounted in the doorway without a load hearing or torque-transmitting central shaft.

In a typical embodiment, a door according to the invention includes upper and lower mechanisms mounted in the doorway about a vertical axis and leaves coupled to the mechanisms such that the leaves are maintained in upright and spaced apart relationship to move as a unit with the mechanisms about the axis. Air sealing means is coupled to at least one of the leaves and the mechanisms for preventing excessive air movement past inner extremities of the leaves.

The invention will be better understood with reference to the drawings, wherein:

FIG. 1 is a perspective view of a typical collapsible revolving door according to the invention;

FIG. 2 is a perspective view of an upper mechanism of the door shown in FIG. 1;

FIG. 3 is a top view of a housing incorporated in the mechanism shown in FIG. 2;

FIG. 4 is a sectional top view on lines 4-4 of FIG.

FIG. 5 is a sectional side view of the door shown in FIG. 1 with the leaves removed; and

FIGS. 6 to 9 are diagrammatic views showing the collapsing of the revolving door in panic conditions.

Reference is first made to FIG. 1 which shows in perspective a typical revolving door 2 according to the present invention. The door 2 includes four leaves 4 mounted to rotate about a vertical axis and coupled to respective upper and lower mechanisms l4, 16. The mechanisms are respectively coupled to a roof l8 and a floor 20 of a doorway. Curved walls 22, 24 extend between the floor 20 and roof 18, the centre of curvature of the walls being the vertical axis between the mechanisms 14, 16. Each of the leaves 4 consists of a plate glass panel 26 bordered at its respective top, bottom and outer edges by heavier members 28, 30 and a lighter member 32. Sealing strips 34, 36 and 38 are attached to respective members 28, 30 and 32 to exclude draughts which would otherwise pass about the leaves 4 and into the building. Inner extremities of the leaves abut against a clear tube 40 of a plastics material which also acts as a draught excluder. The tube 40 is not load carrying but adds to the aesthetic appearance of the door because the combination of the tube 40 and panels 26 give an impression of lightness. As will be evident from subsequent description, the tube 40 is not loadbearing and is not capable of transmitting torsional stresses.

Reference is next made to FIGS. 2, 3 and 4 with particular reference to FIG. 2 to describe upper mecha nism l4 and the connection of the leaves 4 to the mechanism. Because corresponding parts of the leaves and associated parts of the upper mechanism are similar only one leaf will be described. Leaf 4 is attached by its top member 28 to a coupling element 41 which is in turn releasably attached to a leaf pin 42. A cam follower 44 is also attached to the pin 42 and is contained in a generally cylindrical housing 46. The door is shown in the uncollapsed or normal position in which the leaf 4 is held in place by a relatively strong pawl mechanism 48 at an outer end of cam follower 44 adjacent peripheral wall 50.

The coupling element 41 forms a continuation of top member 28 and is coupled to the member 28 by a tongue 43 which engages snugly in a longitudinally extending opening 45 in member 28. Screws 47 prevent separation of the member 28 from element 41.

Each leaf pin 42 has a square lower portion 52, an enlarged and cylindrical intermediate portion 54, and a cylindrical upper portion 56. The lower portion 52 is engaged in an upwardly opening square recess 58 in coupling element 41 and clamped in place by screws 60 adapted to close a slot 62 for gripping the portion 52. Intermediate portion 54 is located in a radial slot 64 machined in an end wall 66 of the housing 46 such that the pin 42 is restrained to rotate and move along a radial path with respect to the vertical axis about which the door rotates.

Upper portion 56 is welded or silver soldered into the cam follower 44 with the cam follower extending in generally parallel relationship with the top member 28 of the leaf 4.

The pawl assembly 48 includes a relatively heavy spring 68 housed loosely in a radially extending opening 70 in cam follower 44. The follower 44 includes a cap 72 removably attached by screws (not shown) and adapted to restrain a ball 74 in engagement with the spring 68. A portion of the ball projects outwardly beyond the cap 72 for engagement in a detent 76 pressed into wall 50. As better seen in FIG. 4, the detent 76 has an cylindrical outer portion 78 engaged in an opening 80 in wall 50 and an enlarged inner portion 82 partially engaged in the wall 50 and having a recess 84. Ball 74 locates in recess 84 to lock the leaf 4 in a preferred position relative to the other leaves. The leaves are broken (i.e., moved from their preferred or uncollapsed position) by forcing their respective balls 74 out of corresponding detents 76 as will be described.

The housing 46 includes a four sided cam 86 having a profile projecting upwardly from end wall 66. As better seen in FIG. 3, the cam 86 has four radial depressions 88 each of which is aligned with a respective one of the slots 64 and detents 76. Four lobes 90 extend radially outwards between slots 64 for combining with narrowed inner end portions 92 of the cam followers 44 to facilitate collapsing the leaves 4 as will be described.

An axial opening 94 in the cam 86 is concentric with an inner surface 98 of the housing wall 50 and includes an axial slot 100 for receiving a key as will be described with reference to FIG. 5.

The springs 68 in the pawl mechanisms 48 are sufficiently strong to retain balls 74 in detents 76 during normal operation of the door. As a result, the leaves 4 are coupled relatively rigidly to the upper mechanism 14 so that this mechanism and leaves 4 move as a unit about the axis of opening 94 in cam 86. The lower mechanism 16 (FIG. 1) is similar to the upper mechanism 14, and is connected coupled to the bottom members 30 in similar fashion to the attachment of upper mechanism 14 to top members 28. The lower mechanism 16 also rotates about the vertical axis of opening 94 in the upper mechanism. However, the means of attachment of the mechanisms 14 and 16 to the respective roof 18 and floor (FIG. 1) are different as will be described next with reference to FIG. 5.

Reference is made to FIG. 5. The upper mechanism 14 is positioned by a key 102 engaged in the slot 100 (FIG. 3) and in a similar slot 104 in a short shaft 106. A bush 108 has an upper outwardly extending flange 110 engaged in a recess 112 in the underside of the mechanism 14 and a bolt 114 passes through the bush 108 and into a threaded opening 116 in the shaft 106 to hold the mechanism 14 on the shaft 106. The key 102 and bolt 114 combine to lock the mechanism 14 on the shaft 106 so that as the door rotates, the mechanism and shaft also rotate. An upper end of the shaft 106 is upset to create a flange 118 which prevents the shaft 106 from passing downwardly through a selfaligning bearing 120 attached by fasteners 122 to an annular disc 124. A ring 123 is positioned on shaft 106 below bearing 120 and locked in place by grub screw 125 to limit upward movement of shaft 106 through bearing 120. Bolts 126 attach disc 124 to an annular top 128 of a casing 130. A ring 132 is attached by screws 134 to a cylindrical casing wall 136 which is in turn welded to the top 128. The ring 132 has upper and lower outwardly extending flanges 138, 140 spaced apart to receive roof 18. In this case, the roof 18 of the doorway is plate glass and a resilient sealing composition 142 is applied between the glass 18 and the flanges 138, 140. However, the casing 130 can be attached to roof 18 by any suitable means depending upon the form of the roof and its situation in the building.

The self-aligning bearing 120 is used in preference to a conventional journal bearing to overcome any misalignment of the mechanism 14 relative to its mounting in the roof 18, and also to avoid possible seizure upon collapsing the leaves 4 (FIG. 1) as will be described.

Returning now to the lower mechanism 16, this mechanism has an annular lip 144 attached by welding or other suitable means. A ring 146 is engaged in an opening 148 in floor 20 and has an annular seal 150 for engaging the lip 144 during rotation of the lower mechanism 16 to prevent dirt falling into the opening 148. The mechanism 16 is engaged by a key 152 on an upper portion 153 of a tubular shaft 154 and rests on an enlarged intermediate portion 156 of the shaft 154. Portion 156 is on a taper-roller thrust bearing 158 sitting in a bearing recess 160 in the top of a cast iron support 162. Shaft 154 has a cylindrical extension 164 projecting through the support 162 and terminating in a squarasectioned end 166 engaged in a gear 168 for driving a speed control 170.

Revolving doors are often speeded up by children and it is preferable to have a speed control 170 which limits the speed of rotation of the doors. However, this speed control does not form part of the present invention but is included for completeness of description.

The shaft 154 of the lower mechanism 16 has an axial opening 172 adapted to receive the tube 40 of a plastics material which is preferably transparent. An upper end of the tube 40 engages about bush 108 and a suitable sealer or adhesive is added to the tube to set it in the shaft 154.

To assemble the revolving door 2, the curved walls 22,24 (FIG. 1) are first positioned relative to a central axis about which the door leaves will rotate and attached to roof 18 and floor 20. Next, the casing 130 is positioned in the roof 18 and adjusted until it is centrally located about the axis of rotation. Using suitable jigs, a line is dropped from the centre of the casing 130 to locate the centre of the lower mechanism 16 and speed control 170. After positioning the speed control 170, the shaft 154 and thrust bearing 158 are positioned with the bearing seated in the cast iron support 162. The shaft 154 should then be centrally located about the axis of rotation. Next, the ring 146 is positioned and then the lower mechanism 16 is dropped over shaft 154 with key 152 in place. The lower mechanism 16 is pushed downwards until it seats on the enlarged intermediate portion 156. Next, in the upper mechanism the annular disc 124 is attached by'fasteners 122 to the self-aligning bearing and the shaft 106 is engaged downwardly through the bearing 120 until the flange 118 engages against the bearing. The ring 123 is then slipped over the shaft 106 into engagement with the underside of the bearing 1.20 and the grub screw is tightened to lock the ring 123 to the shaft 106 and thereby locate the shaft in the bearing 120. The ring 123 should be slightly clear of the bearing 120 to thereby ensure free rotation of the shaft 106 and the bearing 120. The sub assembly so formed in then positioned in the casing andthe bolts 126 engaged through the annular disc 124 and into the annular top 128 to hold the sub assembly in place on the casing 130. Next the upper mechanism 14 is slipped over a lower end of the shaft 106 with the key 102 in place and then the bush 108 is positioned by engaging the bolt 114 in the shaft 106. The assembly of the parts shown in FIG. 5 is completed by engaging the tube 40 in the tubular shaft 154 and pushing it down sufficiently to enable an upper end of the tube to be engaged over the bush 108. The tube 40 is relatively rigid but because of its length has sufficient flexibility to permit this assembly procedure.

Reference is next made to FIGS. 2 and 5 to describe the attachment of the door leaves 4. Firstly,.coupling elements 41 are attached to lower portions 52 of the leaf pins 42 and to corresponding portions of leaf pins in the lower mechanism 16. In all there will be eight coupling elements 41 positioned in generally parallel relationship with corresponding cam followers 44. Screws 60 are tightened sufficiently to hold the elements 41 in place and then door leaves are attached to the elements by engaging element tongues 43 in corresponding openings 45 in top and bottom members 28, 30. Once the tongues 43 are fully engaged in the openings 45, the screws 47 are engaged. These screws preferably pass right through the tongues 43 and are threaded to an opposite side of the members 28, 30.

However, if preferred the screws can simply bear against the tongues 43 to lock them in the openings 45. The position of the leaves in the doorway is checked and then the screws 60 are tightened to complete the assembly.

As previously mentioned, the strength of the springs 68 of the pawl mechanisms 48 is sufficient to hold the door leaves in position during normal use of the door. Also, if the assembly has been carried out accurately, the self-aligning bearing 120 will not be needed and a simple journal bearing could be substituted for it. How ever, if there is any inaccuracy in the assembly, the bearing 120 will permit misalignment so that the door moves freely. This bearing is also useful in ensuring a free breaking of the doors in panic conditions as will now be described.

Reference is next made to FIGS. 6 to 9 to describe the breaking of the leaves during panic conditions. Beginning with FIG. 6 and assuming that a panic has occurred and that people are streaming towards the door in the direction indicated by arrows. When the people contact the leading door leaves 4a, 4b, the pressure on these leaves is transmitted through coupling elements 41 and leaf pins 42 (FIG. 2) to the cam followers 44a, and 44b thereby applying a force tending to dislodge the corresponding balls 74 (FIG. 2) from associated detents 76. When the pressure transmitted through leaves 4a, 4b exceeds the holding power of the pawl assemblies associated with cam followers 44a, 44b, the corresponding balls are forced out of their detents and the cam followers 44a, 44b rotate to the position shown in FIG. 7. As this pivoting occurs, the bottoms of the cam followers 44a, 44b in the housing 46 slide over end wall 66, while the bottoms of the corresponding cam followers in the lower mechanism 16 slide over a corresponding end wall. As soon as the outer ends of the cam followers move away from the inner surface 98 of outer wall 50, the balls therein are urged to their outermost positions by thier corresponding springs but cannot escape from the cam housings because of the retaining caps 72 (FIG. 2).

The movement into the position shown in FIG. 7 has been purely pivotal. However, as the sides of the cam followers 44a, 44b strike the sides of cam lobes 90, the leaf pins are forced to move radially outwardly in the slots 64a, 64b as seen in FIG. 8. This produces a compound sliding and rotational movement of the pins ending when the leaves 4a, 4b strike leaves 40, 4d. The continued pressure from people leaving the building is now applied to leaves 40, 4d causing their pawl mechanisms to give way, and as movement of leaves 4a, 4b continues, the four leaves eventually assume the position shown in FIG. 9 in which the door is fully collapsed and in which each of the leaves is broken. At this point leaf pins 42a and 42b have moved to the outer extremities of respective slots 64a, 64b whereas pins 42c and 42d have rotated without sliding in respective slots 64c, 64d. However, it will be evident that the arrows A could approach the door from any directionand there would be a resulting collapse of the leaves 4 causing some of the pins 42 to move to outer extremities of slots 64.

In order to return the leaves 4 to their uncollapsed or unbroken position, the leaves are simply grasped and moved around until the balls 74 again engage in respective detents 76. As seen in FIG. 4, the detent 76 projects inwardly of the inner surface 98 of wall 50. As a result, when re-positioning the doors in their normal or unbroken positions, the operator will feel the ball 74 engage against the detent 76 and he then knows that he must apply a force to engage the ball in the recess 84. With a little practise the operator will discover how much force is necessary.

When the door leaves are collapsed or broken from their normal position into positions such as shown in FIGS. 7, 8 and 9, the leaves are no longer locked positively to the respective upper and lower housings 46. There is then a tendency for upper housing 46 to become misaligned with the axis of rotation and this is permitted by the bearing to limit the possibility of large frictional forces preventing proper collapse of the leaves. However, as long as at least one leaf remains unbroken, the upper and lower mechanisms will tend to remain in alignment.

Referring to FIG. 6, it is sometimes necessary to break two of the leaves such as 4b and 4d into engagement with respective leaves 4a, 40 to permit access through the door for carrying objects such as stepladders and the like through the door. This can be done by holding the leaf which it is desired to break and moving it suddenly with a large force to break it towards the door against which it is to rest.

The mechanisms 14 and 16 rely for their rigidity on the pawl mechanisms 48 which maintain the upper mechanism 14 in alignment with the lower mechanism 16. In panic conditions, it would be preferable to have one door which tends to remain in the unbroken position until all the other doors are broken in order to ensure that the mechanisms remain in alignment thereby aiding the self-aligning bearing 120 in limiting possible frictional forces. This can be achieved by making the springs 68 associated with one leaf 4 stronger than the other springs. As a result, in panic conditions the door associated with the strongest springs will tend to remain in the unbroken position while the other leaves are broken. Once all three other leaves are broken the force will then be applied to the fourth door having the strongest springs and this will also break. However, because it breaks last, it limits possible frictional forces by maintaining the mechanisms 14, 16 in alignment until the last possible moment.

What we claim as our inventionis:

l. A collapsible revolving door adapted to be positioned in a doorway having a floor and a roof, the door being rotatable about a vertical axis and comprising:

a. upper and lower collapsing mechanisms;

b. upper and lower bearing means coupled to the respective upper and lower collapsing mechanisms:

c. means attaching the upper bearing means to the roof so that the upper bearing means is suspended from the roof with the upper collapsing mechanism located for rotation about said vertical axis;

d. means mounting the lower bearing means in the floor with the lower collapsing mechanism located for rotation about said vertical axis;

e. a plurality of door leaves;

f. means coupling the door leaves independently to the collapsing mechanisms, the door leaf coupling means comprising an upper means connecting the door leaves to the upper collapsing mechanism and a lower means connecting the door leaves to the lower collapsing mechanism, the upper and lower connecting means being independent of one another so that the structural combination of the door leaves and the means coupling the door leaves to the collapsing mechanisms is the only structure provided to limit rotation of one of said collapsing mechanisms relative to the other of the collapsing mechanisms; and

. the collapsing mechanisms including means releasably locating each of the door leaves in an uncollapsed position in which the door leaves are spaced angularly about said vertical axis, each of the door leaves being releasable upon the application of panic forces on the door leaf whereby the door leaf moves into a collapsed position providing direct access past the door.

2. A collapsible revolving door as claimed in claim l in which at least one of said collapsing mechanisms comprises:

a generally cylindrical housing positioned concentrically about said axis and comprising: end wall means having slots therein, each of the slots being associated with a respective one of the door leaves and each slot extending radially outwards;

a plurality of cam followers in said housing, each of the cam followers being associated with a respective one of the door leaves;

said housing further comprising means engageable with the cam followers to limit radial inward movement of the cam followers;

pawl means coupled between each of the cam followers and the housing for normally holding the cam followers in positions corresponding to the uncollapsed positions of the door leaves, the cam followers then being in engagement with the housing limiting means and in radial alignment with the respective slots;

a plurality of leaf pins fixed one to each cam follower at a position adjacent an inner end thereof, each leaf pin projecting through a corresponding one of the slots in the end wall and terminating in a portion adapted to be coupled to a corresponding one of the door leaves with the door leaf aligned with the corresponding cam follower; and

the pawl means including means yieldable upon application of a predetermined force transmitted thereto by a turning force applied to one of the door leaves and transmitted through a corresponding leaf pin and cam follower, to release such cam follower for movement inside the housing whereby continued force on such door leaf will rotate the corresponding leaf pin and cam follower in the housing until rotation of the cam follower is checked by interference with other parts of the mechanism whereupon further force on the door leaf rotates such door leaf and cam follower and also forces the leaf, cam follower, and associated leaf pin to move radially outwards with the leaf pin guided by a corresponding one of the slots.

3. A collapsible revolving door as claimed in claim 1 in which at least one of the collapsing mechanisms comprises:

a housing positioned concentrically about said axis and comprising: a central cam concentric with said axis and an end wall fixed to said cam and having slots therein, each slot being associated with a corresponding one of the door leaves and extending radially outwards from the cam;

a plurality of cam followers in the housing, each cam follower being assiciated with a corresponding door leaf and having an inner end portion normally in engagement with the cam and extending radially outwards in alignment with a respective one of the slots;

pawl means coupled between each cam follower and the housing for normally holding the cam followers in positions corresponding to the uncollapsed positions of the door leaves, the end portion of each cam follower then being held against the cam;

a plurality of leaf pins fixed one to each cam follower at a position adjacent an inner end thereof, each leaf pin projecting through a corresponding one of the slots in the end wall and terminating in a portion adapted to be coupled to a corresponding one of the door leaves with the door leaf aligned with the corresponding cam follower; and

pawl means including means yieldable upon application of a predetermined force transmitted thereto by a turning force applied to one of the door leaves and transmitted through a corresponding leaf pin and cam follower to release such cam follow er for movement inside the housing, whereby continued force on such door leaf will rotate the corresponding leaf pin and cam follower in the housing until a side of the cam follower meets the cam, further force on the door leaf then continuing to rotate the door leaf and cam follower and also forcing the leaf, cam follower, and associated leaf pin to move radially outwards with the leaf pin guided by-a corresponding one of the slots.

4. A collapsible revolving door as claimed in claim 3 wherein said cam has a cam profile face substantially parallel with said axis, said profile face having a radial depression associated with each cam follower, and a lobe between each pair of depressions, each said end portion of said cam followers being rounded to fit within a corresponding one of said profile face depressions and the said side of the cam follower engaging a corresponding one of the lobes when the cam follower is released.

5. A collapsible revolving door as claimed in claim 4 wherein said housing includes a generally cylindrical outer wall fixed to said end wall, the outer wall being concentric with said axis, and in which said cam followers extend substantially to said outer wall when the door leaves are in their uncollapsed positions, said pawl means being coupled between the outer wall and outer ends of the cam followers.

6. A collapsible revolving door as claimed in claim 5 wherein said end wall provides a smooth bearing surface, and each cam follower has a smooth bearing surface to facilitate movement of said cam followers in said housing upon moving the door leaves between said collapsed and uncollapsed positions.

7. A collapsible revolving door as claimed in claim 6 wherein said pawl means comprises: a spring in each said cam follower, a ball retained in each cam follower and urged outwardly by said spring to a position in which the end of said ball projects beyond said cam follower, and depressions in said outer wall in which said balls are normally seated when said door leaves'are in said uncollapsed position.

8. In a collapsible revolving door positioned between a roof and a floor for movement about a vertical axis, and having door leaves normally extending radially in an uncollapsed position for rotation about said axis, the improvement comprising:

upper and lower housings respectively coupled to the roof and floor and positioned concentrically about said axis, each said housing comprising: a central cam concentric with said axis, said cam having a substantially axial cam profile face divided into a concave depression for each door leaf and lobes, there being one lobe between each adjacent pair of concave depressions; and an end wall fixed to said cam and having radial slots therein associated with said cam profile depressions, each said slot extending outwardly from a position adjacent a corresponding cam profile depression; and a substantially vertical outer wall fixed to said end wall and having a cylindrical inner face concentric with said axis;

a plurality of cam followers in each said housing, each cam follower in each housing being associated with a respective one of the door leaves, each cam follower having a rounded end portion at an inner end thereof and of a shape to fit within a corresponding one of said cam profile depressions;

pawl means in each housing and coupled to each cam follower therein for normally holding said cam followers in an uncollapsed position with the end portion of each cam follower located in a corresponding one of said cam profile face depressions with the body of the cam follower extending radially outwardly from such depression and in alignment with a corresponding one of said slots in said end wall;

a plurality of leaf pins fixed one to each cam follower adjacent the end portion thereof, each leaf pin extending vertically through a corresponding slot in said end wall;

coupling elements fixed to respective leaf pins at positions outside said housings, each coupling element extending radially outwardly from said axis in alignment with a corresponding one of said cam followers;

each leaf including means connecting the leaf to a coupling element from said upper housing and to a coupling element from said lower housing thereby connecting such leaf to associated cam followers in the upper and lower housings for movement therewith;

said pawl means including means yieldable upon application of a predetermined force thereto caused by force on a door leaf acting with associated upper and lower coupling elements, leaf pins and cam followers coupled thereto to release such cam followers for movement inside cam housings whereby continued force on such door leaf will rotate its associated leaf pins and cam followers inside said housings until said cam followers strike said lobes on said cams, continued force then moving said leaf pins radially outwardly in associated slots;

means coupling said upper housing to said roof with said upper housing above said leaves, said coupling means comprising: suspension means attached to said roof; and means rotatably connecting said suspension means to said upper housing for rotation of said upper housing about said axis independently of said lower housing; and

a draft excluder coupled to said upper and lower housings for co-operation with inner edges of said door leaves to limit air movement past said inner edges.

9. Apparatus as claimed in claim 8 wherein said pawl means includes: springs arranged one in each cam follower; balls retained one in each cam follower and urged outwardly therein by associated said springs to positions in which ends of said balls project from respective cam followers; and depressions in said outer wall into which said balls are normally forced by said springs with the corresponding door leaves in the uncollapsed positions.

10. In a collapsible revolving door positioned between a roof and a floor for movement about a vertical axis, and having door leaves normally extending radially in an uncollapsed position for rotation about said axis, the improvement comprising:

upper and lower housings respectively coupled to the roof and floor and positioned concentrically about said axis, each said housing comprising: an end wall having radial slots therein each of the slots being associated with a corresponding one of the door leaves; and a substantially vertical outer wall fixed to the end wall and having a cylindrical inner face concentric with said axis;

a plurality of cam followers in each said housing, each cam follower in each housing being associated with a respective one of the leaves, each cam follower having an inner end portion and extending radially outwards in alignment with a respective one of said slots, said housing further comprising: means engageable with the cam followers to limit inward radial movement of said cam followers;

pawl means in each housing, each pawl means being coupled between each of the associated cam followers and the housing for normally holding the cam followers in position corresponding to the uncollapsed position of the door leaves, the cam followers then being in engagement with the housing limiting means, the cam followers normally extending radially outwardly from the limiting means and in alignment with corresponding ones of said slots in said end wall;

a plurality of leaf pins fixed one to each cam follower adjacent the end portion thereof, each leaf pin extending through a corresponding one of the slots in said end wall;

coupling elements fixed to respective leaf pins at positions outside said housings, each coupling element extending radially outwardly from said axis in alignment with a corresponding one of said cam followers;

each door leaf including means connecting the leaf to a coupling element from said upper housing and to a coupling element from said lower housing to connect such leaf to corresponding cam followers in the respective upper and lower housings for movement therewith;

said pawl means including means yieldable upon application of a predetermined force transmitted thereto caused by force on a said door leaf and further transmitted through a corresonding leaf pin and cam follower for movement inside said housing, whereby continued force on such door leaf will rotate said corresponding leaf pin and cam follower inside said housing until rotation of said cam follower is checked by interference with other parts of the mechanisms whereupon further force on the door leaf rotates such door leaf and cam follower and also forces the leaf, cam follower and associated leaf pin to move radially outwards in said one of said slots; and

means coupling said upper housing to said roof with said upper housing above said leaves, said coupling means comprising: suspension means attached to said roof; and means rotatably connecting said suspension means to said upper housing for rotation of said upper housing about said axis independently of said lower housing and a draft excluder mounted for combination with inner edges of the leaves to limit air movement past said inner edges.

11. A collapsible revolving door as claimed in claim wherein said pawl means includes: springs arranged one in each cam follower; balls retained one in each cam follower and urged outwardly therein by associated said springs to positions in which ends of said balls project from respective cam followers; and depressions in said outer wall into which said balls are normally forced by said springs.

12. A collapsible revolving door as claimed in claim 1 in which said means attaching the upper bearing means to the roof comprises: a bearing; a shaft engaged in said bearing and having an enlarged upper end to restrain the shaft from moving downwardly through the bearing, the shaft projecting through the bearing and terminating in a slotted portion adapted to receive a key; said upper collapsing mechanism defining an axial opening adapted to engage over said slotted portion and defining a further slot for receiving said key whereby said upper collapsing mechanism is located against rotation on said shaft; and means locating said upper collapsing mechanism longitudinally on said shaft.

13. A collapsible revolving door as claimed in claim 1 in which said means attaching the upper bearing means to the roof comprises: a self-aligning bearing; a shaft engaged in the bearing and projecting downwardly beyond said bearing, said upper collapsing mechanism being adapted for engagement on said shaft below said bearing; and means locating said shaft in said bearing and in said upper collapsing mechanism whereby said upper collapsing mechanism rotates with said shaft.

14. A collapsible revolving door as claimed in claim 1 in which said upper and lower collapsing mechanisms include means locating a relatively rigid draught excluding element for co-operating with inner extremities of said door leaves to limit passage of air past said inner extremities.

15. A collapsible revolving door as claimed in claim 1 in which said upper and lower collapsing mechanisms include means locating a relatively rigid draught excluding element for co-operating with inner extremities of said door leaves to limit passage of air past said inner extremities, said element being tubular and formed of a relatively transparent plastics material.

16. Apparatus as claimed in claim 8 in which said upper collapsing mechanism coupling means comprises: a self-aligning bearing; a shaft engaged in the bearing and projecting downwardly beyond said bearing, said upper collapsing mechanism being adapted for engagement on said shaft below said bearing; and means locating said shaft in said bearing and in said upper collapsing mechanism whereby said upper collapsing mechanism rotates with said shaft relative to said bearing. 7

17. Apparatus as claimed in claim 8 in which said upper and lower mechanisms include means locating a relatively rigid draught excluding element for cooperating with inner extremities of said leaves to limit passage of air past said inner extremities.

18. Apparatus as claimed in claim 8 in which said upper and lower collapsing mechanisms include means locating a relatively rigid draught excluding element for co-operating with inner extremities of said leaves to limit passage of air past said inner extremities, said element being tubular and formed of a relatively transparent plastics material. 

1. A collapsible revolving door adapted to be positioned in a doorway having a floor and a roof, the door being rotatable about a vertical axis and comprising: a. upper and lower collapsing mechanisms; b. upper and lower bearing means coupled to the respective upper and lower collapsing mechanisms: c. means attaching the upper bearing means to the roof so that the upper bearing means is suspended from the roof with the upper collapsing mechanism located for rotation about said vertical axis; d. means mounting the lower bearing means in the floor with the lower collapsing mechanism located for rotation about said vertical axis; e. a plurality of door leaves; f. means coupling the door leaves independently to the collapsing mechanisms, the door leaf coupling means comprising an upper means connecting the door leaves to the upper collapsing mechanism and a lower means connecting the door leaves to the lower collapsing mechanism, the upper and lower connecting means being independent of one another so that the structural combination of the door leaves and the means coupling the door leaves to the collapsing mechanisms is the only structure provided to limit rotation of one of said collapsing mechanisms relative to the other of the collapsing mechanisms; and g. the collapsing mechanisms including means releasably locating each of the door leaves in an uncollapsed position in which the door leaves are spaced angularly about said vertical axis, each of the door leaves being releasable upon the application of panic forces on the door leaf whereby the door leaf moves into a collapsed position providing direct access past the door.
 2. A collapsible revolving door as claimed in claim 1 in which at least one of said collapsing mechanisms comprises: a generally cylindrical housing positioned concentrically about said axis and comprising: end wall means having slots therein, each of the slots being associated with a respective one of the door leaves and each slot extending radially outwards; a plurality of cam followers in said housing, each of the cam followers being associated with a respective one of the door leaves; said housing further comprising means engageable with the cam followers to limit radial inward movement of the cam followers; pawl means coupled between each of the cam followers and the housing for normally holding the cam followers in positions corresponding to the uncollapsed positions of the door leaves, the cam followers then being in engagement with the housing limiting means and in radial alignment with the respective slots; a plurality of leaf pins fixed one to each cam follower at a position adjacent an inner end thereof, each leaf pin projecting through a corresponding one of the slots in the end wall and terminating in a portion adapted to be coupled to a corresponding one of the door leaves with the door leaf aligned with the corresponding cam follower; and the pawl means including means yieldable upon application of a predetermined force transmitted thereto by a turning force applied to one of the door leaves and transmitted through a corresponding leaf pin and cam follower, to release such cam follower for movement inside the housing whereby continued force on such door leaf will rotate the corresponding leaf pin and cam follower in the housing until rotation of the cam follower is checked by interference with other parts of the mechanism whereupon further force on the door leaf rotates such door leaf and cam follower and also forces the leaf, cam follower, and associated leaf pin to move radially outwards with the leaf pin guided by a corresponding one of the slots.
 3. A collapsible revolving door as claimed in claim 1 in which at least one of the collapsing mechanisms comprises: a housing positioned concentrically about said axis and comprising: a central cam concentric with said axis and an end wall fixed to said cam and having slots therein, each slot being associated with a corresponding one of the door leaves and extending radially outwards from the cam; a plurality of cam followers in the housing, each cam follower being assiciated with a corresponding door leaf and having an inner end portion normally in engagement with the cam and extending radially outwards in alignment with a respective one of the slots; pawl means coupled between each cam follower and the housing for normally holding the cam followers in positions corresponding to the uncollapsed positions of the door leaves, the end portion of each cam follower then being held against the cam; a plurality of leaf pins fixed one to each cam follower at a position adjacent an inner end thereof, each leaf pin projecting through a corresponding one of the slots in the end wall and terminating in a portion adapted to be coupled to a corresponding one of the door leaves with the door leaf aligned with the corresponding cam follower; and pawl means including means yieldable upon application of a predetermined force transmitted thereto by a turning force applied to one of the door leaves and transmitted through a corresponding leaf pin and cam follower to release such cam follower for movement inside the housing, whereby continued force on such door leaf will rotate the corresponding leaf pin and cam follower in the housing until a side of the cam follower meets the cam, further force on the door leaf then continuing to rotate the door leaf and cam follower and also forcing the leaf, cam follower, and associated leaf pin to move radially outwards with the leaf pin guided by a corresponding one of the slots.
 4. A collapsible revolving door as claimed in claim 3 wherein said cam has a cam profile face substantially parallel with said axis, said profile face having a radial depression associated with each cam follower, and a lobe between each pair of depressions, each said end portion of said cam followers being rounded to fit within a corresponding one of said profile face depressions and the said side of the cam follower engaging a corresponding one of the lobes when the cam follower is released.
 5. A collapsible revolving door as claimed in claim 4 wherein said housing includes a generally cylindrical outer wall fixed to said end wall, the outer wall being concentric with said axis, and in which said cam followers extend substantially to said outer wall when the door leaves are in their uncollapsed positions, said pawl means being coupled between the outer wall and outer ends of the cam followers.
 6. A collapsible revolving door as claimed in claim 5 wherein said end wall provides a smooth bearing surface, and each cam follower has a smooth bearing surface to facilitate movement of said cam followers in said housing upon moving the door leaves between said collapsed and uncollapsed positions.
 7. A collapsible revolving door as claimed in claim 6 wherein said pawl means comprises: a spring in each said cam follower, a ball retained in each cam follower and urged outwardly by said spring to a position in which the end of said ball projects beyond said cam follower, and depressions in said outer wall in which said balls are normally seated when said door leaves are in said uncollapsed position.
 8. In a collapsible revolving door positioned between a roof and a floor for movement about a vertical axis, and having door leaves normally extending radially in an uncollapsed position for rotation about said axis, the improvement comprising: upper and lower housings respectively coupled to the roof and floor and positioned concentrically about said axis, each said housing comprising: a central cam concentric with said axis, said cam having a substantially axial cam profile face divided into a concave depression for each door leaf and lobes, there being one lobe between each adjacent pair of concave depressions; and an end wall fixed to said cam and having radial slots therein associated with said cam profile depressions, each said slot extending outwardly from a position adjacent a corresponding cam profile depression; and a substantially vertical outer wall fixed to said end wall and having a cylindrical inner face concentric with said axis; a plurality of cam followers in each said housing, each cam follower in each housing being associated with a respective one of the door leaves, each cam follower having a rounded end portion at an inner end thereof and of a shape to fit within a corresponding one of said cam profile depressions; pawl means in each housing and coupled to each cam follower therein for normally holding said cam followers in an uncollapsed position with the end portion of each cam follower located in a corresponding one of said cam profile face depressions with the body of the cam follower extending radially outwardly from such depression and in alignment with a corresponding one of said slots in said end wall; a plurality of leaf pins fixed one to each cam follower adjacent the end portion thereof, each leaf pin extending vertically through a corresponding slot in said end wall; coupling elements fixed to respective leaf pins at positions outside said housings, each coupling element extending radially outwardly from said axis in alignment with a corresponding one of said cam followers; each leaf including means connecting the leaf to a coupling element from said upper housing and to a coupling element from said lower housing thereby connecting such leaf to associated cam followers in the upper and lower housings for movement therewith; said pawl means including means yieldable upon application of a predetermined force thereto caused by force on a door leaf acting with associated upper and lower coupling elements, leaf pins and cam followers coupled thereto to release such cam followers for movement inside cam housings whereby continued force on such door leaf will rotate its associated leaf pins and cam followers inside said housings until said cam followers strike said lobes on said cams, continued force then moving said leaf pins radially outwardly in associated slots; means coupling said upper housing to said roof with said upper housing above said leaves, said coupling means comprising: suspension means attached to said roof; and means rotatably connecting said suspension means to said upper housing for rotation of said upper housing about said axis independently of said lower housing; and a draft excluder coupled to said upper and lower housings for co-operation with inner edges of said door leaves to limit air movement past said inner edges.
 9. Apparatus as claimed in claim 8 wherein said pawl means includes: springs arranged one in each cam follower; balls retained one in each cam follower and urged outwardly therein by associated said springs to positions in which ends of said balls project from respective cam followers; and depressions in said outer wall into which said balls are normally forced by said springs with the corresponding door leaves in the uncollapsed positions.
 10. In a collapsible revolving door positioned between a roof and a floor for movement about a vertical axis, and having door leaves normally extending radially in an uncollapsed position for rotation about said axis, the improvement comprising: upper and lower housings respectively coupleD to the roof and floor and positioned concentrically about said axis, each said housing comprising: an end wall having radial slots therein each of the slots being associated with a corresponding one of the door leaves; and a substantially vertical outer wall fixed to the end wall and having a cylindrical inner face concentric with said axis; a plurality of cam followers in each said housing, each cam follower in each housing being associated with a respective one of the leaves, each cam follower having an inner end portion and extending radially outwards in alignment with a respective one of said slots, said housing further comprising: means engageable with the cam followers to limit inward radial movement of said cam followers; pawl means in each housing, each pawl means being coupled between each of the associated cam followers and the housing for normally holding the cam followers in position corresponding to the uncollapsed position of the door leaves, the cam followers then being in engagement with the housing limiting means, the cam followers normally extending radially outwardly from the limiting means and in alignment with corresponding ones of said slots in said end wall; a plurality of leaf pins fixed one to each cam follower adjacent the end portion thereof, each leaf pin extending through a corresponding one of the slots in said end wall; coupling elements fixed to respective leaf pins at positions outside said housings, each coupling element extending radially outwardly from said axis in alignment with a corresponding one of said cam followers; each door leaf including means connecting the leaf to a coupling element from said upper housing and to a coupling element from said lower housing to connect such leaf to corresponding cam followers in the respective upper and lower housings for movement therewith; said pawl means including means yieldable upon application of a predetermined force transmitted thereto caused by force on a said door leaf and further transmitted through a corresonding leaf pin and cam follower for movement inside said housing, whereby continued force on such door leaf will rotate said corresponding leaf pin and cam follower inside said housing until rotation of said cam follower is checked by interference with other parts of the mechanisms whereupon further force on the door leaf rotates such door leaf and cam follower and also forces the leaf, cam follower and associated leaf pin to move radially outwards in said one of said slots; and means coupling said upper housing to said roof with said upper housing above said leaves, said coupling means comprising: suspension means attached to said roof; and means rotatably connecting said suspension means to said upper housing for rotation of said upper housing about said axis independently of said lower housing and a draft excluder mounted for combination with inner edges of the leaves to limit air movement past said inner edges.
 11. A collapsible revolving door as claimed in claim 10 wherein said pawl means includes: springs arranged one in each cam follower; balls retained one in each cam follower and urged outwardly therein by associated said springs to positions in which ends of said balls project from respective cam followers; and depressions in said outer wall into which said balls are normally forced by said springs.
 12. A collapsible revolving door as claimed in claim 1 in which said means attaching the upper bearing means to the roof comprises: a bearing; a shaft engaged in said bearing and having an enlarged upper end to restrain the shaft from moving downwardly through the bearing, the shaft projecting through the bearing and terminating in a slotted portion adapted to receive a key; said upper collapsing mechanism defining an axial opening adapted to engage over said slotted portion and defining a further slot for receiving said key whereby said upper collapsing mechanism is located against rotation on said shaft; and means locating said upper collapsing mechanism longitudinally on said shaft.
 13. A collapsible revolving door as claimed in claim 1 in which said means attaching the upper bearing means to the roof comprises: a self-aligning bearing; a shaft engaged in the bearing and projecting downwardly beyond said bearing, said upper collapsing mechanism being adapted for engagement on said shaft below said bearing; and means locating said shaft in said bearing and in said upper collapsing mechanism whereby said upper collapsing mechanism rotates with said shaft.
 14. A collapsible revolving door as claimed in claim 1 in which said upper and lower collapsing mechanisms include means locating a relatively rigid draught excluding element for co-operating with inner extremities of said door leaves to limit passage of air past said inner extremities.
 15. A collapsible revolving door as claimed in claim 1 in which said upper and lower collapsing mechanisms include means locating a relatively rigid draught excluding element for co-operating with inner extremities of said door leaves to limit passage of air past said inner extremities, said element being tubular and formed of a relatively transparent plastics material.
 16. Apparatus as claimed in claim 8 in which said upper collapsing mechanism coupling means comprises: a self-aligning bearing; a shaft engaged in the bearing and projecting downwardly beyond said bearing, said upper collapsing mechanism being adapted for engagement on said shaft below said bearing; and means locating said shaft in said bearing and in said upper collapsing mechanism whereby said upper collapsing mechanism rotates with said shaft relative to said bearing.
 17. Apparatus as claimed in claim 8 in which said upper and lower mechanisms include means locating a relatively rigid draught excluding element for co-operating with inner extremities of said leaves to limit passage of air past said inner extremities.
 18. Apparatus as claimed in claim 8 in which said upper and lower collapsing mechanisms include means locating a relatively rigid draught excluding element for co-operating with inner extremities of said leaves to limit passage of air past said inner extremities, said element being tubular and formed of a relatively transparent plastics material. 